Planetary health diet linked to lower dementia burden
Across countries, a 10-point higher diet score was linked to a 1.32% lower rate of healthy years lost to dementia 10 years later.
Multicentre
An observational study tracked country-level data on older adults in 185 countries and territories at seven time points from 1990 to 2018. Researchers compared four dietary patterns with dementia estimates and diet-related environmental footprints.
A 10-point higher score on the modified Planetary Health Diet Index was associated with a 1.32% lower dementia disability-adjusted life-year rate 10 years later. This measure combines years lived with disability and years lost to early death. The score was not associated with dementia prevalence—the proportion of people with dementia. Higher scores were also linked to 11.39% lower land use and 8.16% lower greenhouse gas emissions, but 3.59% greater water scarcity.
Why it matters
For aging populations, dietary policies must consider both cognitive health and environmental sustainability. The authors said these findings may inform policies tailored to local circumstances.
Caveats
This observational study compared countries, not individuals. It cannot show that people who followed the diet had lower dementia burden or that diet caused the association.
- Planetary health diet
- Alternative healthy eating index dietary pattern
- Dash diet
- Dementia
- Modified Planetary Health Diet Index
- Humans
The paper
Shandong University; Qilu Hospital of Shandong University
The American Journal of Clinical Nutrition, 16 Oct 2026
